激光冲击诱导残余应力预测方法研究

A Study on the Prediction Method of the Residual Stress Induced by Laser Shock Processing

研究基于激光冲击诱导残余应力产生原理,把激光冲击诱导的最终稳定的残余应力看成激光冲击引起的残余应力与为满足平衡而产生的残余应力的代数和,提出了残余应力预测方法。通过激光冲击平板件的残余应力预测发现,模拟结果与实验结果十分接近。说明此方法可实现对工件全尺寸的残余应力预测,为后续的分析提供了条件。另外,对激光冲击处理圆角试样产生的残余应力进行了模拟研究,发现工件的形状对最终稳定的残余应力的分布存在影响,表现为表面应力值和残余压应力的深度发生了变化。说明此方法可能实现激光冲击处理任意形状工件的残余应力预测。

Based on the mechanism of the formation of residual stress generated by laser shock processing （LSP） that the stabilized residual stress is deemed as the superposition of the LSP induced residual stress and the residual stress required to satisfy equilibrium, a methodology was developed to bridge the gap between the simulation of residual stress and the analysis of residual stress. A simple verification was made by comparing the predicted and experimental results in a flat plate, and it shows＇a good agreement between them. This method was also supposed to predict the residual stress resulting in an arbitrary body treated with arbitrary LSP parameters. Residual stress prediction in a corner fillet specimen is presented, and the result shows that residual stress is affected by the shape of the specimen, both the surface stress and the depth of residual compress stress.